LUBBOCK, Texas – Happy animals equal profitable animals. That’s the theory behind the U.S. Agricultural Research Service study of animal comfort, behavior and well-being.
Julie Morrow, research leader and animal ethologist, observes how farm animals act while no one is around. By watching animals in their element, their stress levels can be observed and their immune functions monitored.
Researchers can then determine what’s affecting the animal’s welfare and find ways to improve the environment so the animal is more comfortable and, therefore, more productive.
“Stress is not a bad thing as long as the animal can deal with it and get over it,” Morrow said.
Lion vs. calf. For example, if a lion is chasing a calf, the calf is stressed. When stressed, the body’s response is to pump more blood into the muscles, resulting in more energy. This will help the calf to run faster and get away from the predator, Morrow said.
However, she said if the stress continues, the effect can be ulcers, changes in learning areas of the brain and suppressed immune response. This results in less animal profitability.
Animal stress is determined by changes in activity and aggressiveness, immune function changes and if cortisone is being produced in the brain, she said.
Goals. This observation is part of the USDA’s research service’s program called “Animal Well-Being and Stress-Control Systems.”
According to the Livestock Issues Research Unit, the program aims to improve food safety by changing management methods depending on animal behavior.
Another goal is to “reduce animal stress and improve comfort in production. With measures of behavior, physiology, immunology, endocrinology and health, technology will be developed to define and improve conditions of livestock.”
Livestock watch. Morrow and her colleagues conduct a 24-hour surveillance four times each year studying Texas commercial cattle feed lots. They use a remote camera or sit on a surveillance van’s roof platform with binoculars to check the behavior of each animal every 15 minutes.
All of the surveillance is designed to be discreet so the cattle can be observed in their natural environment. Night-vision scopes are used so bright lights don’t disturb the animals, and prior to the surveillance, the cattle are exposed to the van so they are used to having it nearby.
Conclusions. Morrow has already found that by feeding cattle their main meal in the evening, their aggressive behavior dramatically decreases. If cattle cannot fulfill their natural instinct to eat at night, they became stressed. Therefore, the animals look for other activities to relieve that stress, such as aggressive behavior toward other animals.
She has also found that mixing pigs and cattle causes stress to both species and changes their behavior and immune systems.
“Mixing animals causes a stress response and if done often enough can certainly cause chronic stress,” Morrow said.
Another finding is that pigs housed in traditional confinement are more stressed than pigs living outside.
Up and coming. Morrow is currently at a research unit in Lubbock, Texas, at Texas Tech University studying whether stress impacts food safety. Since bacteria from animals’ stomachs is being found on food, she is looking at whether “chronic stress is responsible for pathogen shedding” and if stress allows the bacteria to harbor.
Morrow and her colleagues are also studying pregnant pigs. Researchers have found that by keeping pregnant pigs together, they are not as stressed; however, in order to keep the pigs together, their aggression toward each other must be reduced.
Pig studies. Another animal behaviorist studying pigs is Dr. Harold Gonyou at the Prairie Swine Center in Saskatchewan, Canada.
Gonyou found that using gentle methods while moving pigs from farm to market will decrease their stress levels and the number of downer pigs.
The test. Gonyou and his colleagues collected data on two groups of pigs. Under the supervision of a humane committee, one group was moved aggressively and the other was moved gently. The aggressive group was moved by an electric prod and yelling, while the gentle group was moved by hollow, plastic tubes and quiet talking.
The pigs in the aggressive group began to show signs of stress quickly. These signs included blotchy skin, panting, vocalization and shaking.
“We knew using electric prods, bunching pigs up and using a steep loading ramp would create stress in the aggressively handled group,” he said. “What we didn’t know is what percentage of pigs would become downers.”
At the conclusion of the study, 20.4 percent of the pigs in the aggressive group were classified as downers. None of the pigs in the gentle group were downers.
The researchers found that aggressive handling causes stress in pigs, which can result in direct losses through declining meat quality and downer animals that cannot be sold.
(You can contact Kristy Alger at 1-800-837-3419, ext. 23, or by e-mail at kalger@farmanddairy.com.)
